Spiral and eccentric groove cutter for phonograph records and the like



May 6, 1952 KQVACH 2,595,795

SPIRAL AND ECCENTRIC GROOVE CUT-TER FOR PHONQGRAPH RECORDS AND THE LIKE Filed April 13. 1949 4 Sheets-Sheet l g? 6/ f 6 9 Q? 436' 6g 8 67 619 r f 30* 37 Q E INVENTOR. 25% g '0? m mzwwm/i m B {9g 72 May 6, 1952 F. J. KOVACH 2,595,795

SPIRAL AND ECCENTRIC GROOVE CUTTER FOR PHONOGRAPH RECORDS AND THE LIKE Filed April 13, 1949 4 Sheets$heet 2 51? 5' Q7 5.9 56 I 65 57 ,55' I 6' 6g i 35' 55 1 I I #9 M l w 37 K 7/ I um 20 2 it 5 B 3Q 6 k ,2

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1711723 J ffozfac/i y 6, 1952 F. J. KOVACH 2,595,795

SPIRAL AND ECCENTRIC GROOVE CUTTER FOR PHONOGRAPH RECORDS AND THE LIKE Filed April 13. 1949 4 Sheets-Sheet 3 INVENTOR.

May 6, 1952 KOVACH 2,595,795

SPIRAL AND ECCENTRIC GROOVE CUTTER F OR PHONOGRAPH RECORDS AND THE LIKE Filed April 13, 1949 4 Sheets-Sheet 4 IN V EN TOR.

Patented May 6, 1952 SPIRAL AND ECCENTRIC GROOVE CUTTER FOR PHONOGRAPH RECORDS AND THE LIKE Frank Julius Kovach, Chicago, Ill., assignor to Rondo Records, Inc., Chicago, 111., a corporation of Illinois Application April 13, 1949, Serial No. 87,252

7 Claims. (01. 33--27) My invention relates to improvements in apparatus for placing spiral and/or eccentric cutoff grooves in a phonograph record or the like.

Phonograph record playing machines which are adapted to change records automatically, utilize a reciprocal motion imparted to the tone arm to actuate the record changing mechanism. In practice, this reciprocal motion is obtained by causing the pickup needle to follow along an eccentric groove placed either within or outside of the principal sound track. Further, it is customary to connect this'eccentric groove to the principal sound track by means of a spiral groove,

so that a record having an eccentric cut-off groove in the center portion thereof has an appearance similar to that of the record illustrated in Figure 16 of the accompanying drawings.

In the manufacture of records for use in phonograph players having automatic change mechanism, the initial step is to place the recording upon a master record blank. In most instances, the sound track will commence near the periphery of the record and proceed inwardly; however, in a few instances the sound track proceeds from the center portion of the record toward the outer periphery thereof. Following this initial step, the manufacturer (or the individual, in the case of recordings made in the home) next places a spiral groove in the record blank, which groove originates from the last portion of the sound track to be cut or embossed in the record blank, and terminates in an eccentric groove of the character mentioned above.

Heretofore, both the spiral and the eccentric cut-off grooves have been placed in the record surfaces either by hand instruments or else by means of special, complicated mechanisms which are adapted for this purpose. Without exception, these latter mechanisms are difiicult to use, partly because of their complex structure. Those which are accurate are so expensive as to be too costly for the average small recording studio or person desiring to make home recordings. Since no two sound tracks are of the same length, it is not practical to provide a die whereby spiral and eccentric grooves may be stamped or pressed into the record surface. When the spiral and eccentric grooves are placed in the record blanks by hand instruments, the results are generally very unsatisfactory. since it requires a great amount of skill to place a smoothly curved groove of uniform depth in the record surface.

The problem which presents itself, therefore,

is the provision of apparatus which is capable of lacing in a record blank both spiral and eccentric grooves of accurate configuration and uniform depth, which apparatus is adjustable to generate spiral and eccentric grooves either at the center of the record or at the periphery thereof, and which is inexpensive to manufacture and easy to use so that its benefits are available to the individual home recorder and the manufacturer of large quantities of records alike.

It is the principal object of my invention to provide apparatus which fully meets and solves this problem.

Briefly I achieve this desirable object by providing apparatus comprising the following principal elements: (1) a member which is adapted to contact the record and to turn therewith, (2) means for setting the first member in at 1east two different positions relative to said record (for example two positions spaced degrees apart), (3) a cutting member carried by said first member and adapted to rotate freely about an axis eccentric of the center axis of the record, and (4) means for adjusting the effective radius arm of the cutting member. When the first mentioned member is set in one position, and the cutting member turns relative thereto, a segment of a spiral is constructed, due to the eccentricity of the cutting member. By setting the first member in the next alternate position and adjusting the radius arm of the cutting member so that said member engages the end portion of the segment just cut, and then again turning the cutting member relative to the first member, another segment is thereby constructed. In this way, a spiral groove can be progressively placed in the record surface. When the spiral is of desired length, the operator then continues to turn the cutting member without changing the-radius arm thereof until it completes one full revolution, or 360 degrees. In this way an eccentric groove is generated. If desired, one or more ad ditional eccentric grooves can be placed within the first eccentric groove to insure proper reciprocation of the tone arm should the pickup needle accidentally slip or jump out of the first eccentric groove.

In order that my invention may be more fully disclosed, reference is had to the accompanying drawings which illustrate several forms of apparatus embodying the foregoing and such other principles, advantages or capabilities as may be pointed out as this description proceeds, or as are inherent in the present invention. For purposes of clarity in exposition, the following de scription is explicit, and the accompanying drawderstood that said exposition is illustrative only, and that my invention is not restricted to the particular details recited in the specification or shown in the drawings.

In the drawings:

Figure 1 is a front elevational view showing one embodiment of my invention;

Figure 2 is a plan elevational view of the embodiment of Figure 1;

Figure 3 is a side elevational view of the same;

Figure 4 is a front elevational view taken substantially in section on the line 44 of Figure 2, showing my invention as it appears in use;

Figure 5 is a plan elevational view of that element of the embodiment of Figures l-4 which is adapted to turn with the record;

Figure 6 is a bottom elevational view of the element of Figure 5, with a portion thereof broken away;

Figure 7 is a front elevational view of a second embodiment of my invention;

Figure 8 is a plan elevational view of the same;

Figure 9 is a fragmentary view taken in sec tion on the line 9-9 of Figure 7;

Figures 10-l5 illustrates somewhat schematically the manner in which my invention may be used to place a spiral and eccentric cut-off groove in a record; and

Figure 16 illustrates the appearance of a record in which a spiral and eccentric groove has been placed by means of the present invention.

Like reference numerals designate like parts in the drawings and in the description thereof following hereafter.

Referring now to the drawings, Figures l-6 illustrate one embodiment of my invention which is particularly well suited for use in phonograph recording studios, and in other situations where a high degree of accuracy and ease in adjustment are desirable. This embodiment is shown as including a base 20 of substantially cylindrical configuration, having a recessed bottom 2|, and a center opening 22 adapted to fit over the center spindle of a turntable, as for example the center spindle 23 projecting upwardly from the turntable 23 of Figure 4. Figure 4, taken in conjunction with Figure 6, shows the center opening 22 to be eccentrically located from the center of the cylindrical base 20. Two other openings 25 and 26 are also placed in the base 20, and:

are spaced equidistant from the opening 22 and spaced angularly from each other substantially 180 degrees apart. Each of the openings 25 and 25 is adapted to mate with the record drive lug 21 conventionally forming part of the turn-Z" table 25. The base 20 also includes a radial bore 93 which is counterbored and internally threaded to receive the set screw 94 (Figure 6).

Referring now to Figures 4 and 5, the base 20 is further shown as having a thrust bearing sur--" face 28, an annular groove 29, a journal bearing surface 30 concentric with the center of the base 25, and an upper bearing surface 3!. Said surface 3| is broken by three openings 32 spaced approximately 120 degrees apart (Figure 5).?

surface 37, a projecting annular ring 38 and a bore preferably dimensioned such that there is a snug fit between said bore 39 and the journaled bearing surface 30. The upper member 35 thus pivots about an axis which is eccentric of the center line of the center opening 22 in the base 25. The upper member 35 further includes a center opening adapted to receive the fastener 5| whereby the upper member 35 is held against the spring loaded ball bearings 33, said fastener 4| threading into the internally threaded hole 42 in the base 20. Normally, the springs act on the ball bearings 35 to cause upward displacement of the upper member 35 along the journal bearing surface 3!]; hence there normally is a small clearance between the thrust bearing surfaces 28 and 31. The precise degree of clearance between these surfaces 28 and 31 may be accurately set through adjustment of the fastener ll.

The upper surface of the member 35 is provided with two holes 43 and 44. The hole 44 preferably extends through the member 35 (Figure 4), so that oil or other lubricants can be supplied to the interior bearing surfaces of the device without dismantling the member 35 from the base 20. A post 45 is press fitted within the hole 43 and acts as a vertical guide member along which the arm 46 may be moved. Said arm 45 is substantially perpendicular to the post 45, and is locked in place thereon by tightening down the knob 41, thereby pressing the collar 48 against the post 45. A look washer 49 is interposed between the collar 48 and the knob 41, to lock the knob 41 in place. Extending upwardly from the arm 46 is a finely threaded screw 53. An adjusting nut 5| carried by the yoke 5| engages the screw 53, the yoke 5| being locked to the post 45 by the thumb screw 53. A stop 54 on the post 45 prevents accidental removal of the yoke 5| therefrom when it is being adjusted along said post 45. To accurately position the arm 46 on the post 45, the knob 51 is backed off and the adjusting nut 5!! turned to move the arm 46 along the post to the desired position. The knob 41 is then tightened to lock the arm in place.

The arm 45 is prevented from turning relative to the post 45 by the dog 55, one leg 56 of which is slidable in the hole 54. The other leg 51 of the dog 55 is anchored within the screw threaded bayonet sleeve 53 which is tightened down upon the leg 57 by the nut 59.

As is best shown in Figures 2 and 3, the projecting end of th arm 45 is provided with a fiat Bil which is inclined from the plane of the bottom 2| of the base 25. A toolholder 5| is positionable along the arm 45, being securely fastened thereto by tightening the knob 62 against the lock washer 63 and its associated collar 64. The lower portion of the toolholder 5! contains a screw threaded bayonet sleeve 65 which is adapted to be contracted upon screwing the nut 66 upwardly. A finely threaded screw 51 extends to one side of th toolholder 5| and is threadably engaged by the adjusting nut 53 carried by the yoke 69. A thumb screw Til secures the yoke '65 in place on the arm 35. Referring now to Figure 4, an adapter sleeve extends downwardly from the bayonet sleeve 55, and carries a cutting member '12. Said member 72 is held securely in place by the thumb screw 13 which engages the keyway M.

It is this cutting member 72 which either cuts or embosses the desired spiral and eccentric cutoff grooves in the record I5, depending upon'the shape of the cutting member 12 and the material from which the record is formed. In the particular construction shown, th cutting angle of the cutting member 12 is determined in large measure by the angle of inclination of the flat 60, since the toolholder BI is substantially perpendicular to the fiat 66 (Figure 3). In general, a cutting angle approximately to degrees results in efficient cutting or embossing of the materials from which records are customarily formed. It will be apparent to those skilled in this art, however, that other cutting angles than those shown or mentioned may be used.

Advantageously, the effective radius arm of the cutting member 12, or that distance between the cutting tip 18 of said member I2 and the center of rotation of the upper member 35, may be adjusted both accurately and quickly. By backing off the knob '62 and the thumb screw 1!], the toolholder 6| andyoke 69 may be moved along the arm 46 until the cutting member 12 is approximately in position. The thumb screw 10 is then tightened, to anchor the yoke 69 to the arm 46, after which the adjusting nut 68 is used to locate the tcolholder 6| precisely. When the latter position is reached, the knob 62 is tightened and the whole assemblage is made rigid.

A second embodiment of my invention having a somewhat simpler and less expensive construction than the embodiment of Figures l-6, is shown in Figures 7-9. The principal difference between these two embodiments resides primarily in th construction and adjustment of the cutting member 12 relative to the upper member 11, the base being utilized in both embodiments. Similarly, the undersurface of the upper member 11 may be made identical with the corresponding portion of the upper member 35. Unlike the upper member 35, however, the member 11 is provided with a pedestal 18 having a substantially horizontal hole 19 therethrough. A rod 80 having a knurled grasping portion 8| at one end thereof is movable within the hole 19, and is anchored in place by the thumb screw. An

eccentric 83 extends from the opposite end of the rod 80 and supports the tcolholder 84, said holder 84 being anchored to the eccentric 83 by the thumb screw 85. As in the case of the embodiment of Figures l-G, an adapter sleeve H extends from the toolholder 84 and carries the cutting member 12, the thumb screw 13 holding the cutting member !2 in place. Further as in the embodiment of Figures l-6, the clearance between the bearing surfaces 28 and 31 is adjusted by;

means of the'fastener 4!. The effective radius arm of the cutting member 12 of Figures 7-9 is adjusted by moving the rod 80 relative to the pedestal 18. The vertical adjustment of the cutting member 12 is achieved by turning the rod f 80, thereby rotating the eccentric B3 to raise or lower the tool holder 84, depending upon the direction of rotation (Figure 9).

The manner in which my invention may be used to place a spiral and/ or eccentric groove in the surface of a record will be more readily perceived by reference to the specific illustration of Figures 10-1-5. Thus, in the initial step, shown schematically in Figure 10, apparatus corresponding to the embodiment of Figures 7-9 is.

placed uponthe record 15 so that the center opening 22 (in the lower base 25) mates with the center spindle 23, while the opening 25 engages the record drive lug 21. The effective radiusarm of. the cutting member 12 is then adjusted so that said member 12 engages the last groove of the sound track 86. The clearance between the tip 1'5 and the record 15 is then adjusted, so that the tip 76 just clears the surface of the record when the apparatus is in the inoperative position (see Figure 4). The clearance between the thrust bearing surfaces 28 and 31 is then adjusted, bearing in mind that the depth of the groove is equal to the last mentioned clearance less the clearance between the tip :6 and the record 15.

Following this, the operator grasps the upper member 11 and presses down upon the same until the thrust bearing surfaces 28 and 31 are in sliding contact, and then rotates the turntable 24 through 180 degrees. In this fashion the record 15 may be rotated through one-half revolution relative to the upper member H. The indexing marks 81 (see Figure 3) spaced at 180 degree intervals may be used to turn the turntable 24 through precisely 180 degrees to this new position, at which point the operator may relax the downward pressure on the upper member I1. When the record 15 has reached this latter position (shown in Figure 11), the drive lug 21 has also rotated through 180 degrees. Since the axes of rotation of the base 29 and the upper member 11, respectively, are eccentric of each other, and since the axis of rotation of the base 20 has shifted across the axis of the upper member 11 (indicated by the fastener 4|) and toward the cutting member 12, the spiral segment a-b is constructed.

Following this step, the base 20 is removed from the record [5, turned through 180 degrees, and replaced, the drive lug 21 this time being mated with the opening 25. The upper member 11 is then turned 180 degrees, Without marking upon the record, and the effective radius arm of the cutting member 12 shortened until the cutting tip 76 overlies the end I) of the spiral segment a-b (Figure 12). Again the upper member 11 is depressed by the operator to cause the cutting member H to engage the record 15, following which the record is rotated through another 180 degrees in the direction shown in Figure 13. The axis of rotation of the base 20, (exemplified by the center opening 2),-again shifts across the axis of rotation of the upper member 71 and toward the cutting member 72. In this fashion another segment bc of the spiral is constructed (Figure 13) The operator then continues to follow the same procedure, alternating the position of the base 20 relative to the spindle 23 and the drive lug 21, and constructs the spiral segments cd and d-e (Figure 14). When the segment de has been completed, the drive lug 27 will bein the position shown in Figure '14. The operator once again reverses the position of the base 20 relative to the record 15 and again shortens the eflective radius arm of the cutting member E2. The record is then rotated in the direction shown in Figure 15, the first degrees of rotation producing the spiral segment e1. Instead of stopping, howeccentric groove 89. The completed spiral and eccentric grooves, as they appear in a record 9| reproduced from the record 75 is shown in Figure 16. The area 92 shown therein represents the label conventionally placed within the eccentric grooves.

Again referring to Figure 16, it is apparent that as the pickup needle of the tone arm contacts the last portion of the sound track 86, that said needle thereupon spirals inwardly toward the center spindle-23 until it contacts the first eccentric groove 89. Normally the needle stays within the groove 89, however, if for any reason the needle is jarred from the groove 89 it will fall Within and be retained by the second eccentric groove 90. As the record continues to revolve about the spindle 23, a reciprocal motion is imparted to the tone arm, which motion is utilized to actuate appropriate record changing mechanism, to which reference is made above.

It will be apparent to those skilled in the art that the techniques illustrated in Figures 10-15 may also be used in the generation of spiral and eccentric cut-oil grooves at the outer edge or a record, in the event that the sound track proceeds from the inner portion of said record toward the periphery thereof.

While the great majority of recording apparatus include a drive lug such as the lug 2?, in some instances (for example older machines and the less expensive home recording units) no drive lug is provided. Where this is the case, the

base may be held fixed with respect to the record 15, and in a plurality of alternate positions, by means of the set screw 94. Thus, instead of repositioning the base 20 by engaging a drive lug in alternate drive lug holes, the set screw 94 is backed off, the base 20 repositioned with respect to the record I5, and the set screw 94 then tightened against the record spindle 23.

Having thus fully disclosed my novel apparatus for placing spiral and eccentric cut-01f grooves in a record surface, and demonstrated its utility by reference to a specific illustration of the manner in which it is used, I claim as my invention:

1. Mechanism for placing spiral and eccentric cut-off grooves in a phonograph record which fits over a spindle and is rotated by means of a drive lug, comprising: a base member having a planar bottom surface adapted to abut said record, said base member being further characterized by cylindrical bearing surface perpendicular to said bottom surface and an upper, thrust bearing surface parallel to said bottom surface, said bottom surface having a first opening therein eccentric of the axis of said cylindrical bearing surface and engageable with said spindle, and two other openings spaced equally from said first opening, each of said other openings being engageable with said drive lug, and further being spaced angularly from each other approximately 180 degrees; a cap member having an internal bore adapted to be journaled by said cylindrical bearing surface, said cap member further having a lower thrust bearing surface adapted to mate with said upper thrust bearing surface, spring means urging said thrust bearing surfaces apart, means for adjusting the maximum clearance between said thrust bearing surfaces, a post projecting upwardly from said cap member, said post being perpendicular to said lower thrust bearing surface, an arm perpendicular to said post and adjustable therealong, means for securing said arm against rotation relative to said.

cap member, and a toolholder carried by said arm and adjustable therealong.

2. Mechanism for placing spiral and eccentric cut-ofi grooves in a record drivably engaged with the center spindle and a drive lug of a turntable, comprising: a base member having a planar bottom surface adapted to abut said record, said base member being further characterized by a cylindrical bearing surface perpendicular to said bottom surface and an upper thrust bearing surface parallel to said bottom surface, said bottom surface having a first opening therein eccentric of the axis of said cylindrical bearing surface and engageable with said center spindle, and two other openings spaced equally from said first opening and each engageable with said drive lug, said two other openings being further spaced angularly from each other approximately degrees whereby said base member may be alternately positioned on said record in first one and then the other of two diametrically opposed positions; a cap member having an internal bore adapted to be journaled by said cylindrical bearing surface, said cap member further having a lower thrust bearing surface adapted to mate with said upper thrust bearing surface, spring means urging said thrust bearing surfaces apart, means for adjusting the maximum clearance between said thrust bearing surfaces, a post projecting upwardly from said cap member, said post having a cylindrical bore therethrough perpendicular to said axis of rotation, a rod slidable and rotatable in said bore, means for clamping said rod in said post, an eccentric extending from one end of said rod, a toolholder rotatable about said eccentric, and means for clamping said toolholder to said eccentric.

3. Mechanism for placing spiral and/ or eccentric cut-off grooves in a record having a center spindle and a drive lug extending therethrough, comprising: a first member and a second member each rotatable about a common axis, said first member having a planar surface perpendicular to the axis of rotation common to said members, said planar surface having an opening therein eccentric of said common axis, said opening being engageable with said center spindle, said planar surface further having two other openings therein spaced equally from said first opening and each drivably engageable with said drive lug, said two other openings being further spaced angularly from each other approximately 180 degrees, whereby said first member may be fixed relative to said record in each of two diametrically opposite positions, an arm secured to said second member and disposed substantially perpendicular to said axis of rotation, and a tool holding member adjustable along said arm.

4. Mechanism for placing spiral and/ or eccentric cut-off grooves in a phonograph record driven through a drive lug, comprising: a first member having a substantially planar siu'face adapted to contact said record, means for mounting said member on said record for rotation about a first axis, said surface further having a plurality of openings therein spaced equally from said first axis, adjacent openings subtending equal arcs about said first axis, each of said openings further being drivably engageable with said drive lug, whereby said first member may be fixed relative to said record in a plurality of positions, a second member, means for mounting said second member on said first member for xrotation about :a second a-xiswhich is eccentric of said first axis, an arm carried by said second member, said arm being secured against rotation relative to said second member and disposed substantially perpendicular to said axis eccentric of said first axis, means (for adjusting the vertical height of said arm relative to said record, and a tool holder adjustable along said arm.

5. Mechanism for placing spiral and/or eccentric cut-off grooves in a record having a center spindle and a drive lug extending therethrough, comprising: a first member having a base and a cylindrical bearing surface perpendicular thereto, said base having a first opening therein engageable with said center spindle, said first opening being eccentric of the axis of said bearing surface, said base further having two or more other openings therein each of which is equispa-ced from said first axis and drivably engageable with said drive lug, any two adjacent openings of said other openings being spaced the same distance apart, whereby said first member may be fixed relative to said record in a plurality of positions, a second member rotatable about said cylindrical bearing surface, an arm secured to said second member substantially perpendicular to said axis of said cylindrical bearing surface, and a cutting member adjustable along said arm.

6. Mechanism for placing a spiral and eccentric cut-off groove in a record having a center spindle and a drive lug extending therethrough, comprising: a first member having a bottom surface adapted to abut said record and an upper thrust bearing surface parallel to said bottom surface, a second member rotatable relative to said first member about an axis perpendicular to said bottom surface, said second member having a lower thrust bearing surface adapted to contact said upper bearing surface, spring means urging said bearing surfaces apart, means for limiting the clearance between said bearing surfaces, said first member having a first opening therein eccentric of said axis of rotation and engageable with said center spindle and two other openings therein spaced equally from said first opening and engageable with said drive lug, said two other openings further being spaced angularly from each other approximately 180 degrees, whereby said first member may be alternately fixed relative to said record in diametrically opposite positions, an arm carried by said second member and secured against turning relative to said second member, a tool holding member carried by said arm and positioned eccentrically of said axis of rotation, and means for adjusting th eccentricity of said tool holding member.

7. Mechanism for placing spiral and/or eccentric cut-off grooves in a record having a center spindle and a drive lug extending therethrough, comprising: a first member having a bottom surface adapted to abut said record, a second member rotatable relative to said first member about an axis perpendicular to said bottom surface, said first member having a first opening therein eccentric of said axis of rotation and engageable with said center spindle, said first member also having a plurality of other openings in said bottom surface spaced equally from said first opening, adjacent openings of said other openings subtending equal arcs about said first opening as a center, whereby said first member is alternately drivably engageable with said record drive lug in a plurality of different positions, an arm carried by said second member and secured against turning relative to said second member, a tool holding member carried by said arm and positioned eccentrically of said axis of rotation, and means for adjusting the eccentricity of said tool holding member.

FRANK JULIUS KOVACH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,342,872 Sandell June 8, 1920 1,801,404 Will Apr. 21, 1931 1,930,358 Helmenstein Oct. 10, 1933 2,142,436 Clabeaux Jan. 3, 1939 2,368,908 Witter et al. Feb. 6, 1945 2,493,511 Van Eps Jan. 3, 1950 FOREIGN PATENTS Number Country Date 87,961 Germany 1896 

